Holster unit mark??
 

Trying to puzzle out what might be a unit mark on a 1913 AWM holster. Above the maker mark it is marked B ST N and underneath that it is a one over 13. The holster is still an undyed brown color and came with a 1911 dated DWM Luger marked to a Bavarian Artillery zu Fuss unit. Pictures of the markings to follow. Thanks for any help.

I would be very interested in seeing photos of both the holster and pistol. I have two 1911 DWMs marked to the 1st Bavarian Artillery zu Fuss and one matching holster.